Case Description—4 dogs were treated with dexrazoxane for known or suspected doxorubicin extravasation. Records were retrospectively reviewed. Doses and number of doses of dexrazoxane were variable. Dexrazoxane was administered within 2 hours after known extravasation in 3 dogs and 48 hours after suspected extravasation in 1 dog. Additional medical treatments included tissue cooling in all dogs, topically administered dimethyl sulfoxide ointment in 3, and orally administered piroxicam in 1.
Clinical Findings—Mild erythema and edema at the extravasation site developed within 1 to 6 days after extravasation in the 3 dogs that received dexrazoxane within 2 hours after extravasation. Extensive tissue necrosis occurred in the dog treated 48 hours after suspected extravasation.
Treatment and Outcome—Only the dog with severe tissue necrosis required surgical intervention. Lesions in the other 3 dogs resolved with medical management alone. All dogs survived the event.
Clinical Relevance—To date, use of dexrazoxane in the management of doxorubicin extravasation has not been reported in dogs. Treatment was successful in 3 of 4 patients. The most effective dosage and timing of administration are unknown; however, there is evidence to suggest that administration within 6 hours after the event is warranted. Further studies are needed to confirm efficacy and to optimize use of this drug in the prevention and treatment of anthracycline extravasation injury in veterinary patients.
Objective—To determine whether the addition of doxorubicin chemotherapy affected the outcome of cats with incompletely excised, nonvisceral soft tissue sarcomas undergoing postoperative radiotherapy.
Design—Retrospective case series.
Procedures—Medical records were reviewed for clinically relevant data on cats that underwent postoperative radiotherapy for treatment of incompletely excised soft tissue sarcomas with or without concurrent doxorubicin chemotherapy. Radiotherapy was performed on an alternate-day schedule, with a total dose of 58.8 to 63 Gy delivered in 21 fractions. Doxorubicin was administered every 21 days for 3 to 5 cycles. Follow-up information was obtained by means of physical examination or through telephone conversations with refer-ring veterinarians or owners.
Results—Median disease-free interval with concurrent radiotherapy and doxorubicin chemotherapy (15.4 months; range, 2.4 to 44.9 months) was significantly longer than median disease-free interval with radiotherapy alone (5.7 months; range, 1.0 to 50.8 months). However, survival time was not significantly different between groups.
Conclusion and Clinical Relevance—Results suggested that doxorubicin chemotherapy may play a role in extending the disease-free interval in cats undergoing radiotherapy for treatment of incompletely excised soft tissue sarcomas.